1. Field of the Invention
This invention relates to the design and fabrication of conveyor rollers, and more particularly to conveyor rollers having reduced noise levels and long wear life.
2. Description of the Prior Art
The art of conveyor rollers is well-developed. The following representative patents define the state of the art prior to the present invention.
U.S. Pat. No. 2,317,742 granted to Donbeck et al described a conveyor roller for use in steel mills having a case-hardened, polished steel body giving high resistance to wear while shielding the transported medium from scratching or marring.
U.S. Pat. No. 2,761,547 granted to Gehrer described a conveyor or feed roller having a plurality of identical annular roller elements consisting of inner and outer annular members made of steel and intermediate annular members made of rubber. Gehrer's roller was designed to accommodate work pieces of widely varying sizes.
U.S. Pat. No. 3,054,163 granted to Lakin described a roller consisting of a plurality of discs made of fabric-reinforced, resilient rubber (such as tire casings) mounted on a shaft and anchored by metal discs between the rubber discs to prevent displacement of the flexible discs.
U.S. Pat. No. 3,451,112 granted to Karmell et al described a rubber covered steel mill roller with a steel core having a finished protective coating of hard acid-resistant fibrous glass reinforced polyester resin and an outer cover consisting of a performed fibrous glass reinforced resin lined rubber sleeve.
U.S. Pat. No. 3,646,651 granted to McGaughey et al described a conveyor roller for use in corrosive environments consisting of a hollow tubular core structure, a corrosion-resistant resin layer adhered to the core structure, a layer of fiberglass material adhered to the resin layer, an additional layer of resin material impregnating and covering the fiberglass material, another layer of a mat formed from at least one of the group consisting of fibrous crocidilite, asbestos, and polyvinyl chloride-acrylonitrile copolymer covering the second resin layer, and another layer of the resin material impregnating and covering the second mat layer. This roller was designed for use in conditions typified by varying abrasive conditions, elevated temperatures, or any type of chemically corrosive conditions such as relatively high or relatively low pH environments.
U.S. Pat. No. 4,015,320 granted to Meckel et al described a roller for the pressure treatment of webs of goods having a rigid roller core and hose-shaped roller mantle of rubber with reinforcing inserts, in which the reinforcing inserts include a steel wire coil wound concentrically and steel wire layers which are arranged parallel to each other and extend in the axial direction. The Meckel et al roller was designed to eliminate undesired deformation of the elastomeric cover on rollers intended for the processing of paper or textile or for rotary printing machines which are subjected to various forces, primarily radially directed pressure and pushing or sheering forces originating from frictional contact.
Other roller constructions are described in U.S. Pat. No. 1,447,648 granted to Deulin, U.S. Pat. No. 2,253,141 granted to Schofield, U.S. Pat. No. 3,401,439 granted to Staats et al, and U.S. Pat. No. 3,577,315 granted to Franklin.